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Über dieses Buch

The focus of the Congress will be leading-edge manufacturing processes. Topics include manufacturing at extreme speed, size, accuracy, methodology, use of resources, interdisciplinarity and more. Contributions from production and industrial engineering are welcome. Challenges from the areas of manufacturing, machines and production systems will be addressed.

Production research constantly pushes the boundaries of what is feasible. The Congress "Production at the leading edge of technology" will highlight production processes that are advancing into areas that until recently were considered unfeasible, also in terms of methodology, use of resources and interdisciplinarity.

But where does the search for new limits lead? Which limitations do we still have to overcome, which ones do we not want to overcome?

The aim of the German-speaking colloquium is to establish connections between the research locations and to intensify the overall transfer of results and experience with industrial users.

Inhaltsverzeichnis

Frontmatter

Correction to: Production at the leading edge of technology

For a number of chapters the editors’ names were inadvertently captured in the HTML files instead of the chapter authors’ names. The affected chapters as listed below have now been corrected.

Jens Peter Wulfsberg, Wolfgang Hintze, Bernd-Arno Behrens

Forming Machine Tools and Manufacturing Processes

Frontmatter

Overcoming Limits - Die Forging of Cast Preforms

Grenzen überwinden - Gesenkschmieden gegossener Vorformen

Casting and forging are among the technologies with the highest material and energy requirements. Many efforts have been made to minimise the expenditures involved, but in most cases they have been limited to the individual application case. While the combination of casting and forming processes has been described and applied extensively for aluminium components, this approach has been far less investigated and advanced for steel components. The latest developments in the software with a direct interface between casting and forming simulation enabled the creation of a continuous simulation from the casting to the finished forged part. The match between the simulation and the real component was verified on the basis of manufactured sample parts. Currently ongoing investigations focus on the formation of the microstructure in the component. At the same time, the process chain casting - forging is being developed and evaluated for a further component. This approach overcomes existing limits and opens up new possibilities for component design by linking simulations of casting and forging technologies into an integrated continuous process chain simulation.

Uwe Böhmichen, Tim Lehnert, Nadine Schubert, André Wagner, Andreas Sterzing, Reinhard Mauermann

Manufacturing of optical surfaces by burnishing of PMX170CrVMo18-3-1

Herstellung optischer Oberflächen durch das Glattdrücken von PMX170CrVMo18-3-1

Manufacturing of workpieces with a surface roughness of Rt ≤ 0.5 μm by milling is time-consuming and cost-intensive. The burnishing technology with spherical tools made of single crystalline diamond (SCD) is an appropriate process to improve the surface roughness with a high level of efficiency. Furthermore, the burnishing tools can be used after the milling process in the same machine tool and optical surfaces can be machined economically. In the presented investigations the ELMAX steel PMX170CrVMo18-3-1 was burnished after the milling process and the hardness H as well as the surface roughness were investigated. Thereby, minimal values of the surface roughness with Rt = 0.34 μm and Ra = 0.06 μm, depending on the initial surface roughness, were determined and a maximum increase of the hardness H by 5 % could be reached.

Yves Kuche, Dennis Siebel, Julian Polte, Mitchel Polte, Eckart Uhlmann

Influence of shot peening materials on the topography, surface integrity and friction of hot forging tools

Einfluss des Strahlguts auf die Topographie und Reibung, an Werkzeugen der Warmmassivumformung

Due to a complex load spectrum of mechanical, thermal and tribochemical loads, hot forging tools are subject to increased wear. This results in cost-intensive reworking and possibly unscheduled machine downtimes. To reduce wear, research is currently being carried out on combinations of cooling lubricants and adjusted surface topographies in addition to diffusion and coating treatments. The aim of this contribution is to influence the friction between the workpiece and the tool surface by means of adapted surface topographies including cooling lubricant and thus to reduce tool wear. For this approach, tools were manufactured whose surfaces were treated with different shot peening materials and finally used in cylinder and ring compression tests under forging conditions. In order to draw conclusions on a potential influence of the friction conditions depending on the surface topography, the friction factors with lubricant application were determined with the help of the geometric changes of the ring samples after the forging process. The surfaces were also measured 3-dimensionally and the results from the optical analyses and the friction factor determinations were compared with different shot peening materials. The knowledge gained provides information on the application potential of differently conditioned surfaces in the field of hot bulk metal forming.

Tom Petersen, Lennard Lippold, Bernd-Arno Behrens

Investigation of dry lubrication systems for lightweight materials in hot forming processes

Untersuchung von Trockenschmierstoffen für thermisch unterstützte Umformprozesse von Leichtbauwerkstoffen

In the automotive industry, growing demands for lightweight solutions lead to new materials and forming methods. Because of the high specific strength and low density, high-strength aluminum alloys like 7xxx series have a big potential for safety-relevant components, in the future. With the help of thermal supported forming operations like hot forming and quenching, complex part geometries are realizable. The high formability compared with the lower forming forces and reduced springback, as well as a subsequent hardening step enables the production of complex parts. Currently, this forming process is reaching its limits because of high adhesive wear during forming. Therefore industrial use is not suitable at the moment. New developed dry lubrication systems enable hot forming operations without the generation of toxic emissions and a reduction of the adhesive wear. Therefore, different dry lubricants with varying particle size have been analyzed for deep drawing operations under quenching conditions. The influence of the particle size on the applicable lubrication thickness and the necessary consumption has not been analyzed before. Aim of this research is the characterization of different dry lubricant particle size distributions for hot forming and quenching of high-strength aluminum alloys.

Nikolaos Rigas, Friedhelm Junker, Erik Berendt, Marion Merklein

Process Development for the Remanufacturing of Geared Components

Prozessauslegung zur Wiederaufbereitung verzahnter Komponenten

The importance of saving resources and reducing CO2 emissions is continuously increasing in the current and future development of products. In addition, the ever-increasing guidelines lead to the need to increase the efficiency of manufacturing and recycling processes, so that current production adheres to these guidelines. To that end, the product recycling of steel components is a realistic approach to save a high amount of energy, while also ascertaining environmental protection.Departing from this motivation, this paper addresses the process design for the re-manufacturing of gears from their worn-out state by using bulk metal forming technologies. For this purpose, a Matlab script was created, which calculates a simplified stochastic damaged gear contour according to the elementary wear mechanisms for spur gears. Based on these results, strategies for precision postforming and proper tooling were determined with the aim to remanufacture gears.

Philipp Kuwert, Kai Brunotte, Bernd-Arno Behrens

Material characterisation as a basis for material modelling for heat treatment during roll forming

Werkstoffcharakterisierung als Grundlage zur Materialmodellbildung für die Wärmebehandlung beim Walzprofilieren

Roll forming enables the production of profile-shaped components, e.g. for the automotive industry. By integration of heat treatment into the continuous manufacturing process, an alternative to roll forming of full martensitic steels has been developed which enables both the production of fully hardened profile components and locally hardened areas in longitudinal and transverse direction of the parts. On the one hand, process integration leads to a shorter process time, to the reduction of production costs and to an improvement in component quality. On the other hand, due to the high process speed during roll forming, heat treatment has to be achieved in a very short time, thus representing a technological challenge.In order to design the process and predict the final mechanical component properties (hardness, microstructure, etc.), it is necessary to integrate the precipitation, recrystallization and grain growth processes associated with the high heating rates in a material model. In fundamental investigations for the development of the material model, cold preformed strips of 22MnB5 were heated under different heating conditions – conventional in the furnace and inductive at different heating rates – and then quenched in water. The initiation of recrystallization and grain growth processes as a function of the heating rate could be detected. Based on this, a reaction kinetic model was developed to describe the influence of static recrystallization on the mechanical properties.

Anna Guk, Andreas Kunke, Verena Kräusel

Investigations of forming force, friction values and surface qualities in ring compression tests using oscillating tools

Untersuchungen zur Umformkraft, Reibwerten und Oberflächengüten bei Ringstauchversuchen mit oszillierenden Werkzeugen

An innovative forming process for the production of a functional component with internal and external gearing was developed at the Institute of forming Technology and Machines (IFUM) in the framework of the project A7 „dynamic Process Forces“ of the special research area TR73. The process is characterized by the new manufacturing technology sheet-bulk metal forming (SBMF). This technology combines a sheet- and bulk metal forming operation in which the semi-finished material is sheet metal. By combining these two technologies, the process limits can be extended. In order to reduce the friction between component and tool and to increase the surface quality of the component, superimposed oscillation is applied to the SBMF process. A hydraulically operated vibrating device was used to generate the oscillation overlay. For the identification of optimal oscillation parameters, ring compression tests have been carried out. The aim of these investigations was to analyze the influence of superimposed oscillation on the surface roughness as well as on friction characteristics. Therefore, frequency and amplitude of the oscillation superposition have been varied. In addition, the difference between lubricated and non-lubricated semi-finished materials has been analyzed. The surface roughness of the ring compression test samples was measured on a surface profilometer. The friction factors were calculated based on the geometrical parameters of the ring compression samples. The friction coefficients were also identified by numerical simulation. In addition, the influence of the oscillation parameters on the forming force was examined. The experimental results confirmed the initially assumed positive influence of oscillation.

Philipp Müller, Daniel Rosenbusch, Jörn Wehmeyer, Sven Hübner, Bernd-Arno Behrens

Investigations on Residual Stress Generation in Extruded Steel Components

Untersuchungen zur Eigenspannungsentstehung in fließgepressten Stahlbauteilen

During the forming of components, inhomogeneous stress conditions lead to residual stresses, which influence the operating behaviour of the manufactured part. Compressive residual stresses generally have a positive effect, while tensile residual stresses reduce the fatigue strength and facilitate crack initiation. Full forward extrusion has been established as an industrial manufacturing technique, where cylindrical billets are formed in the die and ejected in opposite direction. In order to influence the residual stresses state, it is essential to know about its formation. A basic understanding is created by separate investigation of the forming and the ejection step. In the context of this paper, singlephase ferritic stainless steel X6Cr17 and ferritic-austenitic duplex steel X2CrNi- MoN22-5-3 are used. The quantification of the residual stresses states is carried out by X-ray diffractometry, for which a measurement method for duplex steel is validated. The influence of forming and ejection is determined separately by manufacturing components with and without an ejection operation.

Andreas Jobst, Christoph Kiener, Marion Merklein

Development of a Design Tool for Servo-Powertrains in Forming Presses

Entwicklung eines Auslegungstools für Servo-Antriebe in Umformpressen

In modern manufacturing industry, the factors of competition cannot be reduced to a small number. Although the most obvious ones seem to be time and costs, over the years, flexibility became an aspect of manufacturing not to be underestimated. One way of providing the mentioned flexibility was to use servoelectrical machines as drives for forming presses in the beginning of the century [1]. A higher efficiency, a higher output rate or an adjustable ram stroke profile are just some of the advantages this technology brings over conventional forming presses [2,3]. In modern manufacturing industry, the factors of competition cannot be reduced to a small number. Although the most obvious ones seem to be time and costs, over the years, flexibility became an aspect of manufacturing not to be underestimated. One way of providing the mentioned flexibility was to use servoelectrical machines as drives for forming presses in the beginning of the century [1]. A higher efficiency, a higher output rate or an adjustable ram stroke profile are just some of the advantages this technology brings over conventional forming presses [2,3].

André Höber, Bernd-Arno Behrens, Richard Krimm

Characterization of temperature-dependent tension-compression asymmetry for high-strength aluminium alloys

Charakterisierung der temperaturabhängigen Zug- Druck-Asymmetrie von höherfesten Aluminiumlegierungen

In the course of lightweight construction, modern materials with high strength and low density are essential. High-strength aluminium alloys such as 7000 series aluminium alloys meet these requirements but are only limited formable at room temperature. Thus, different heat assisted sheet metal forming processes are used to increase the formability. First investigations on the highstrength aluminium alloy AA7075 show a temperature-dependent and tensilecompressive asymmetric material behaviour. Since both tensile and compressive forces occur in sheet metal forming processes, an understanding of temperaturedependent tension-compression asymmetry is vital to set up material models for process design. Until now, the tension-compression asymmetry has barely been investigated for high-strength aluminium alloys at different temperatures. Therefore, further experimental studies are necessary. Within this contribution, the material behaviour of AA7020-T6 and AA7075-T6 is hence examined under uniaxial tensile and compressive load at different temperatures.

Peter Hetz, Marion Merklein

Enhanced accuracy in springback prediction for multistage sheet metal forming processes

Gesteigerte Vorhersagegenauigkeit bei der Rückfederungsberechnung mehrstufiger Blechumformverfahren

Structural car body components made of advanced-high-strength steels (AHSS) offer a high potential for lightweight design, while meeting increased requirements regarding crash performance simultaneously. However, manufacturing the dedicated parts using conventional deep-drawing processes often results in a high amount of shape deviation after removing the part from the tool. A concept for reducing this springback was developed at the IFU Stuttgart. The approach consists in a modification of the draw bending process by alternating the blank draw-in.

David Briesenick, Mathias Liewald, Ranko Radonjic, Celalettin Karadogan

Autoadaptive Minimization of Transfer System Oscillations

Autoadaptive Minimierung von Schwingungen in Transfersystemen

Complex sheet metal parts are produced in sequential forming operations on transfer presses. To minimize downtimes, transfer systems transport the workpieces between the forming stages automatically in the auxiliary process times. In order to achieve a high productivity, forming machines are operated with high stroke rates. As a result auxiliary process times are reduced, so that transfer systems have to be moved with high speed [1].

Stefan Fries, Thang Nguyen, Levent Altan, Dietmar Friesen, Richard Krimm, Bernd-Arno Behrens

Rotational Molding for the Production of Hybrid FRP Metal Tension and Compression Rods with Form Fit

Schleuderverfahren zur Herstellung von hybriden FKV Metall Zug-Druck-Stangen mit Formschluss

One innovative production process for manufacturing rotationally symmetric FRP-metal components, such as drive shafts or tension and pressure rods, is the rotational molding process. In comparison to common joining processes, such as bonding or screwing, the metallic components and the fiber-reinforced plastic part can be intrinsically joined during the forming process. This saves production time and cost compared to conventional joining processes.

Jonas Nieschlag, Paul Ruhland, Sven Coutandin, Jürgen Fleischer

Characterisation of Self-Regenerative Dry Lubricated Layers on Mo-Basis by Nano Mechanical Testing

Charakterisierung von selbstregenerativen trockengeschmierten Schichten auf Mo-Basis durch nanomechanische Prüfung

For the application in dry lubricated rolling bearings the development of self-regenerative molybdenum oxide layers is necessary. The self-regenerative coatings should provide a hard overcoat in the tribological contact due to oxidative processes. The application of the Mo-layers on the conventional bearing steel (AISI 52100) is carried out by means of physical vapour deposition (PVD). The characterisation of layers in the nanometre range is highly demanding and close the measurable limit.

Norman Heimes, Florian Pape, Gerhard Poll, Dennis Konopka, Simon Schöler, Kai Möhwald, Bernd-Arno Behrens

Validation of numerical simulations for the reduced freeform bending process using a test bench

Validierung numerischer Simulationen des reduzierten Freiformbiegeprozesses mit einem Prüfstand

Freeform bending provides a wide range of possibilities to design complex bending parts based on tubes as well as on profiles. Currently, common inefficient trial-and-error procedures are used for designing and manufacturing freeform bending parts. Numerous iterations, consisting of subsequent real tests, are needed to achieve accurate parts within the tolerances and with the intended quality. The compensation of deviations during the trial-and-error procedure mostly depends on the operator’s experience instead of defined and transferable methods.

Matthias Konrad Werner, Daniel Maier, Simon Vitzthum, Carsten Intra, Wolfram Volk

Investigation of the forming limit behavior of martensitic chromium steels for hot sheet metal forming

Untersuchung der Grenzformänderung martensitischer Chromstähle für die Warmblechumformung

A possible alternative to the established press hardening steel Usibor 1500 (22MnB5) are hot formed martensitic chromium steels. The combination of strength and ductility of the martensitic chromium steels can be adjusted to an extreme level. By this means conventional lightweight solutions can be enhanced and this leads to a more economical use of resources. Furthermore, the extreme strength combined with the higher ductility provides an extreme crash safety of the produced car body parts.

Eugen Stockburger, Hendrik Wester, Johanna Uhe, Kai Brunotte, Bernd-Arno Behrens

Experimental Investigation of Inserts in SMC Foam Sandwich Structures for Aircraft Interior Applications

Experimentelle Untersuchung zur Integration von Inserts in SMC-Schaum-Sandwich-Strukturen für den Einsatz in der Flugzeugkabin

Sandwich structures made of fibre reinforced plastics offer a high potential for lightweight design and are widely used in aircraft cabin applications. To face the challenge of the increasing demand in new aircraft, a new manufacturing technology for sandwich structures based on Sheet Moulding Compound (SMC) in combination with a rigid foam core has been developed, allowing the efficient and low cost manufacturing of complex sandwich components in a compression moulding process. For the joining of sandwich components, a well-established method is the integration of threaded metallic inserts that enable a detachable join and thus a high efficiency with regard to assembly, repair and maintenance processes. In the conventional manufacturing of sandwich components, these inserts are usually integrated in a subsequent step after the actual manufacturing of the structure. This process is characterised by a large amount of manual work. The SMC Foam Sandwich technology, on the other hand, offers the potential for a direct integration by moulding in the inserts in the compression moulding process. In this paper an experimental investigation is presented comparing the two concepts for the SMC Foam Sandwich technology with regard to the cycle times as well as mechanical properties of the joins.

Jesper Buck, Marc Mayer, Marc Fette

Electromagnetic Forming of Design Elements

Elektromagnetische Umformung von Design Elementen

Nowadays, many industries have to distinguish themselves from other players in the market through innovative products and product designs. This also concerns aerosol cans. Therefore, suppliers seek solutions for producing individualized cans by embossing brand logos. Due to the almost fully exhausted deformation limits during the production of aerosol cans, this is hardly possible via conventional forming processes. As a high-speed technology, electromagnetic forming is a very promising method for overcoming the manufacturing limits of conventional processes. The paper shows a design for a tool for embossing aerosol cans. It gives insight into existing challenges and shows how to avoid or overcome them. An experimental verification proves the feasibility of the process and demonstrates that difficult forming operations are perfectly feasible with special forming processes like electromagnetic forming.

Maik Linnemann, Verena Psyk, Christian Scheffler, Welf-Guntram Drossel

Influence of Increased Manganese Content on the Precipitation Behaviour of AISI H10 in Thermomechanical Fatigue Tests

Einfluss eines erhöhten Mangangehalts auf das Ausscheidungsverhalten von 1.2365 in thermomechanischen Ermüdungsuntersuchungen

Nitriding as well as the application of hard coatings are common surface layer modifications to reduce wear of forging dies and thereby increasing tool’s lifetime. This study aims for increasing forging dies wear resistance by alloying a hot-working tool steel (AISI H10) with manganese. A reduction of the material-specific ac1b-temperature has been shown in previous investigations and facilitates cyclic surface reharding effects by cyclic thermomechanical loading. This paper deals with the influence of the alloying element manganese on the precipitation behaviour of carbides during cyclic thermomechanical loading and their positive influence on thermomechanical fatigue, hardness, impact toughness as well as maximum true stress in compression tests. As a result, the manganesemodified hot-working tool steel AISI H10 showed a more homogenous distribution of precipitated carbides. In addition, the material modification resulted in an advantageous thermomechanical fatigue behaviour and has not shown a stress drop after cyclic thermomechanical loading. Especially at elevated temperatures an increased maximum true stress and impact toughness was achieved by manganese alloying the hot-working tool steel AISI H10.

Serdal Acar, Oleksandr Golovko, Mark A. Swider, Florian Nuernberger, Martin Siegmund, Jan Puppa, Alexander Chugreev, Bernd-Arno Behrens

Manufacturing of Hybrid Solid Components by Tailored Forming

Herstellung hybrider Bauteile durch Tailored Forming

Constantly increasing requirements for technical components considering strength, functional integration, lightweight construction as well as saving resources lead to the demand for high-performance components with locally adapted properties. In order to meet these requirements, the combination of different materials within one component is of major importance. Within the Collaborative Research Centre (CRC) 1153, innovative process chains are being developed to realise a new class of hybrid solid components. In contrast to existing manufacturing processes of hybrid solid components, where the joining process takes place during forming or at the end of the process chain, tailored semi-finished workpieces are used, which are joined before the forming process. This results in a geometric and thermomechanical influence on the joining zone during the forming process which cannot be created by conventional joining techniques. In the scope of this work the Tailored Forming approach is defined and an overview of the applied joining, forming and finishing steps is given as well as a short summary of the accompanying design and evaluation methods.

Johanna Uhe, Bernd-Arno Behrens

Thermal characterization of metallic surface contacts: New test rig for determination of the interfacial heat transfer coefficient at intermediate temperatures

Thermische Charakterisierung von metallischen Oberflächenkontakten: Neuer Versuchsstand zur Bestimmung des Wärmeübergangskoeffizienten bei mittleren Temperaturen

Nowadays numeric methods, such as finite element method, are utilised to optimise production procedures of high-end materials and thereby increase existing production limits. Metal forming is an example for these procedures because it is an application where processes are continuously optimised. The knowledge of accurate boundary values is of high importance for the numeric optimisation of metal forming processes. For the simulation of transient heat transfer, as it often occurs in forming processes, various experiments have been developed in the past to determine these boundary conditions. The optimisation of a process based on the entire process chain also requires the precise knowledge of the interfacial heat transfer coefficient (IHTC) of previous processes. However, these IHTC values are often only known in an inaccurate value range. For that reason, a test rig for a one-dimensional, steady state heat transfer was developed. With this test rig it possible to determine the IHTC at intermediate temperatures and low contact pressures. Furthermore, essential variables can be examined via a variation of the atmosphere and the surface conditions. The generated heat is conducted via temperature resistant punches to a stack of samples, while the temperature distribution is measured. The multi-layered stacking of the samples generates a high number of identical surface contacts, which increases the resulting measurement accuracy. Thus, the IHTC can be determined by knowing the thermal conductivity of the materials and the temperature measurements.

Juergen A. Nietsch, Jan E. Menzler, Stephan Hojda, Wolfgang Lenz, Marco Teller, Herbert Pfeifer, Gerhard Hirt

Towards Nonstop Availability in Roll Forming through Digitalization

Mit Digitalisierung auf dem Weg zu permanenter Verfügbarkeit beim Walzprofilieren

With the progressive implementation of Industry 4.0, many established manufacturing processes are qualified to meet new market requirements such as shorter product life cycles, smaller batch sizes and increased flexibility. Due to complex adjustment tasks, roll forming requires long set-up and troubleshooting times. The recording of process characteristics gained by sensor networks contributes to an improved understanding of the process. The evaluation of monitored data using machine learning allows for faster error detection, which in turn reduces costs and increases overall equipment effectiveness as well as product quality.In this paper, a single-step roll forming process is investigated. Deliberate misalignments of the roll forming stands are arranged in order to find correlations between process states and sensory data. In this context, force measurement and different torque measuring systems are compared regarding their applicability and accuracy in roll forming. Thereby, a correlation between profile cross section and monitored sensory data can be shown. In order to enable fast data evaluation a supervised machine-learning environment is set up. An ensemble of random subspace classifiers uses the proven correlations to predict the investigated misalignments. It can be shown that force data with a prediction rate of 92.6% are better suited than torque data for monitoring a single-step process. With these results, the software generates correction proposals that support the operator.

Marco Becker, Peter Groche

Forging of Extremely Finely Grained Microstructure Materials by Use of Thermomechanically Treated Base Material

Schmieden von hochgradig feinkörnigem thermomechanisch behandeltem Vormaterial

The newly developed forging process chain is based on a thermomechanically treated base material with an optimum microstructure at the edge of the nano-scale. It is associated with maximum properties in terms of high strength and excellent toughness. This offers the possibility of a novel and extraordinarily energy-efficient process chain of manufacturing of highly loaded and safety relevant parts in all kinds of machinery. Therefore, it is necessary to shape the thermomechanically treated base material, with its superior properties, without a loss to the near net shape part. Hot and warm forging processes are known as appropriate and efficient for the forming of high strength materials while also ensuring the materials’ formability is not overstressed through strain hardening. Within this paper it could be shown that the original microstructures were maintained, and in some cases improved. Therefore, a targeted heating strategy and a warm forging process were designed. The characterisation and numerical modelling of the novel material is presented and the effects of heating and forming on the microstructure of the pre-treated base material are shown in microsections. The influence on the resulting mechanical properties such as the significant increase of roughly 150 J (+400 %) in the notch impact energy (compared with forged parts from untreated material) are detailed described. Additionally, the influence of forming parameters on the microstructure such as effective plastic strain and forming temperatures are discussed.

Julian Diefenbach, Tim Matthias, Kai Brunotte, Bernd-Arno Behrens

Extremely smooth: how smooth surfaces enable dry and boundary lubricated forming of aluminum

Extrem glatt: Wie glatte Oberflächen eine trockene und grenzgeschmierte Umformung von Aluminium ermöglichen

Reducing the amount of lubricant down to dry frictional contact in aluminum forming still poses major challenges for research and industry. The (partially) dry frictional contact favors aluminum adhesion on the tools. Coating the tools with a:C-H (hydrogenated amorphous carbon) can lead to significant improvements, but recent findings show a surprising effect of both tool and sheet surface roughness and topography on the friction and wear behavior. This publication analyzes the friction and wear behavior of coated and uncoated tool and sheet surfaces for both dry and minimal lubricated applications. On the sheet side, the roughness of the sheet metal EN-AW 5083 is significantly reduced by polishing to Rz values in the range of 0.2 μm. Various phenomena are evident: Due to the reduced surface roughness, a by 50% improved coefficient of friction is achieved at low loads and plane-plane-contact even with smallest possible lubricant quantities. In the dry case, however, the surfaces show slight signs of wear. In the high load case both friction is significantly reduced to a coefficient of friction of 0.01 and no wear present on the tool surface both in the dry and minimally lubricated cases. The phenomena are attributed to the complex smoothing behavior of the surface topography and are analyzed based on surface parameters.

Felix Flegler, Peter Groche, Tim Abraham, Günter Bräuer

Cutting Machine Tools and Manufacturing Methods

Frontmatter

Shape alterations and their holistic geometrical representation in abrasive flow machining

Holistische Abbildung der Gestaltänderung infolge des Strömungsschleifens

Abrasive flow machining is a suitable manufacturing process for deburring, edge rounding and surface finishing applications. In this paper, the alterations of the form as a result of abrasive flow machining are presented. The alteration of the form is only one example for the reproduction of geometrical changes. Others could be seen in the changes of surface roughness or waviness. Moreover, a verification strategy for a holistic understanding of the interaction between the micro and macro geometry is introduced. In this sense, the term quality is enhanced. The findings are used to develop process models and simulations in consideration of the correlation between the machining parameters and the examined geometrical properties. These process models will be used to accelerate the process design, thus reducing costs incurred by time, work and material for necessary experiments.

Simon Roßkamp, Eckart Uhlmann, Robert Hofmann, Sophie Gröger

Micro milling of areal material measures: Influence of the manufacturing parameters on the surface quality

Mikrofräsen flächenhafter Kalibriernormale: Einfluss der Fertigungsparameter auf die Oberflächenqualität
Katja Klauer, Matthias Eifler, Benjamin Kirsch, Jörg Seewig, Jan C. Aurich

Additive manufacturing for intelligent lightweight tools

Intelligente Leichtbauwerkzeuge durch additive Fertigung
Kim Torben Werkle, Walther Maier, Hans-Christian Möhring

Drive Unit Enabling Electrochemical Orbiting with High Dynamics and High Accuracy

Hochdynamische und hochgenaue Antriebseinheit für das elektrochemische Orbiting (EC-Orbiting)
René Wulfsberg, Hendrik Rentzsch, Oliver Georgi, Gunnar Meichsner, Willy Peter, Jan Edelmann

Concept to analyze residual stresses in milled thin walled monolithic aluminum components and their effect on part distortion

Konzept zur Analyse der Eigenspannungen in gefrästen, dünnwandigen, monolithischen Aluminiumbauteilen und deren Einfluss auf den Bauteilverzug
Daniel Weber, Benjamin Kirsch, Christopher R. D’Elia, Barbara S. Linke, Michael R. Hill, Jan C. Aurich

Experimental Analysis of the Friction Behaviour in Cutting

Jannis Saelzer, Andreas Zabel, Dirk Biermann

Mutability of cutting materials – performance of niobium carbide based hard metals

Wandlungsfähigkeit von Schneidstoffen – Leistungsfähigkeit von niobcarbidbasierten Hartmetallen
Kristin Kropidlowski, Daniel Hinzmann, Eckart Uhlmann, Géraldine Thomas Gradt

Recognition of wood and wood-based materials during machining using acoustic emission

Materialerkennung von Holz und Holzwerkstoffen während der Zerspanung mittels Körperschall

With increasing automation and the striving for individual products with highest quality requirements, the demand for self-regulating processes in wood processing has increased. The recognition of the material must be taken into account when adjusting the process parameters in order to achieve the desired cutting quality. In the processing of wood and wood-based materials, inhomogeneity and batch scattering are challenges in terms of process monitoring and control. In order to achieve a reliable quality, it is necessary to carry out material recognition automatically in process. Investigations have shown that recording structure-borne sound is useful to differentiate the type of wood and wood-based materials. On the basis of, e.g. image recognition and the use of machine learning methods, the material can be identified within a very short time. This information can be used for setting the optimum process parameters.

Sarah Eschelbacher, Jonas Duntschew, Hans-Christian Möhring

Pre- and post-treatment of HVOF-WC-CoCr-coated HSS cutting parts in order to substitute sintered cemented carbide cutting tool materials

Vor- und Nachbearbeitung von HVOF-WC-CoCr beschichteten HSS Zerspanwerkzeugen als Alternative zu gesinterten Hartmetallwerkzeugen

High-performance cutting tools generally consist of sintered solid cemented carbide, mostly based on tungsten carbide and cobalt. To produce the macrogeometry of shank tools, such as drilling or milling tools, carbide blanks are ground in various operations. Therefore, a considerable amount of material removal and long machining times are required. The shortage and the minor diversified supplier base of tungsten motivate the development of alternative concepts in the field of cutting tool materials. In this context, a new and innovative solution is to substitute the sintered solid carbide with HVOF-WC-CoCr coated cutting parts based on hardened high-speed steel. This method allows hardened high-speed steel to be used in machining beyond its material-specific limits. This saves costs and reduces environmental impact by less tungsten removal. To pursue this solution approach, the coating specific properties as well as the adjustment for the applications have to be investigated fundamentally.Subject of this paper is the preparation steps of the cutting edges based on hardened high-speed steel according to the application of the HVOF-WC-CoCr coating. In order to accomplish this, grinding and wet abrasive jet machining processes are used. After the coating is applied, a suitable topography of the coating has to be produced by grinding for further machining processes. The paper presents investigations according to the ensued topographies. In the end, the main results are summarised. Therefore, the most favourable preparation parameters according to the post-treatment for HVOF-WC-CoCr coating are presented.

Karolin Kamplade, Robert Aßmuth, Dirk Biermann

Orthogonal Turning Simulations for Casted Steel Alloy Using Mesh Free Methods

Orthogonale Drehprozesssimulationen für Stahlgusslegierungen mit Netz-freien Methoden

Automobile components have to fulfil comprehensive requirements in terms of functional performance, reliability and production cost which are at the leading edge of technology. For that, they often undergo machining operations. Robust, high-precision machining processes are critical to the reduction of scrap rates which severely affect the cost per part. Owing to this reason, computational modelling of machining by means of the Finite Element Method (FEM) has gained increased emphasis in recent years in order to enhance process design and optimization. A major drawback of FEM in modelling of machining, however, is the handling of mesh distortions which are inherent to cutting processes. In contrast, mesh-free methods such as Smooth Particle Hydrodynamics (SPH) or Smooth Particle Galerkin (SPG) methods eliminate this drawback. Hence, this paper focuses on the mesh-free simulation of orthogonal turning of a recent cast steel alloy using the SPH and SPG methods. Simulations of variable particle diameters do indicate low do to be favorable for both methods. Forces and chips from mesh-free simulations were compared against FEM simulation and experimental results. Simulations in LS-DYNA and experiments both using Design of Experiments (DoE) were carried out in order to investigate the effects of cutting velocity, feed and rake angle on force components, which demonstrate good agreement of results from mesh-free simulations and tests. With the mesh-free methods the effort to model the machining process was significantly decreased compared to the FEM, however at the expense of higher computation time. In future, mesh-free methods, especially SPG, can significantly improve the efficiency of the machining process layout reducing today’s mostly experimental expense, which arises in particular for recent materials, thereby contributing to the production at the leading edge of technology.

Pulkit Rana, Waldemar Zielasko, Thomas Schuster, Wolfgang Hintze

Safety of slim tool extensions for milling operations at the limit

Sicherheit schlanker Werkzeugverlängerungen für spanende Bearbeitungsverfahren im Grenzbereich

The use of slim tool extensions (STEs) in manufacturing processes has become an important factor for productivity considering complete machining of complex workpieces. Operating errors, e.g. that lead to a crash, can cause plastic deformation of STEs during the machining operation and therefore lead to an increased moment of inertia, as well as an increased rotational energy due to the machine tool’s spindle speed controller. Currently used machine tool enclosures are not designed to withstand such failures with regards to the increase in kinetic energy. Due to the possible exposure of the operator to the identified hazard and the corresponding severity of the harm, the hazardous situation is associated with a high risk. In this paper, the failure scenarios are identified and modeled. This includes the calculation of elastoplastic deformations of STEs based on finite element analysis and analytical calculations of the kinetic energy of rotating deformed STEs. As an exemplary result the operating limits of STEs for a HSK 40/50 tool holder are presented. Based on the described model a parameter study and a sensitivity analysis were carried out. For experimental validation of the described model a speed-up test stand is presented. Lastly, measures for risk reduction in accordance with the three-step method are suggested.

Simon Thom, Eckart Uhlmann

Automated Assembly and Robotics

Frontmatter

Influence of filler wire oscillation on the seam texture in laser beam brazing

Einfluss der Zusatzdrahtoszillation auf die Nahttextur beim Laserstrahlhartlöten
Thorsten Mattulat, Helge Kügler, Frank Vollertsen

Highspeed Force Sensitive Object Handling via Cyberphysical Gripping System

Einfluss der Zusatzdrahtoszillation auf die Nahttextur beim Laserstrahlhartlöten
Michael Miro, Miguel Angel Villanueva Portela, Bernd Kuhlenkötter

Overview and Classification of Defects occurring during Laser Beam Melting of Nickel-base Alloys

Übersicht und Klassifizierung von Defekten beim Laser- Strahlschmelzen von Nickelbasislegierungen
Mathias Sebastian Palm, André Chandelle, Fabian Riss, Michael F. Zaeh

Fast Pick and Place Stacking System for Thin, Limp and Inhomogeneous Fuel Cell Components

Schnelles Pick and Place Stapelsystem für dünne, biegeschlaffe und inhomogene Brennstoffzellen-Bauteile
Paul Bobka, Felix Gabriel, Martin Römer, Thomas Engbers, Markus Willgeroth, Klaus Dröder

Higher deposition rates in laser hot wire cladding (LHWC) by beam oscillation and thermal control

Erhöhung der Abschmelzleistung beim Laser- Heißdrahtbeschichten mittels Strahloszillation und temperaturbasierter Regelung
Dieter Tyralla, Thomas Seefeld

Challenges in bonding processes in the production of electric motors

Herausforderungen bei Klebeprozessen in der Herstellung von Elektromotoren

In an effort to meet climate protection targets, countries around the world are promoting electro mobility. As a result of market growth, the worldwide production capacities for electric motors for traction drives is going to expand significantly. Besides, the existing technology must be adapted to automotive- specific life cycle requirements. On the product side, the electric machine has to reach maximum power densities in order to keep the required limitations of space and weight. Furthermore, a fully automated production process is essential to achieve high output rates and required quality standards. The application of new adhesives and bonding processes implements product-relevant properties in the production of components for electric motors. Moreover, the selection of adhesive systems and process parameters is crucial for cost-efficient and high quality manufacturing processes in mass production. In the production of permanent magnet synchronous machines, adhesives are used for joining of lamination stacks, fixation of magnets and the overall assembling of stator housings.The paper analyses and evaluates different adhesive systems in terms of their product and process capability using two cases of application. The results serve as a starting point for further automated process development and reveal the challenges of the adhesive application in production technology for electric motors.

Johannes von Lindenfels, Marco Ziegler, Maximilian Kneidl, Alexander Kuehl, Joerg Franke

Synchronization of Scrum and Stage-Gate in Hybrid Product Development Projects of Manufacturing Companies

Synchronisation von Scrum und Stage-Gate in hybriden Entwicklungsprojekten produzierender Unternehmen

More than ever, manufacturers today face dynamic business environments and volatile customer requirements. As a result, many companies are trying to adapt agile development methods that originated in the software industry and have shown to improve development productivity and time-to-market. Since a holistic application of agile methods to physical product development is rarely possible, manufacturers tend to selectively combine agile methods like Scrum with existing Stage-Gate processes in a so-called hybrid development process. Agile methods, however, contradict the sequential character of Stage-Gate development processes, so that the challenge lies in the successful synchronization of these two fundamentally different development approaches. The paper addresses this problem and provides a framework to determine the structural and contextual compatibility of Scrum and Stage-Gate as well as their project-specific, optimal proportion. In that, it provides guidance and assistance on how to combine the two development approaches efficiently and effectively.

Marius Krug, Johanna Ays, Frederick Sauermann, Jan-Philipp Prote, GüCnther Schuh

Robot-based automated production of wrapped connections with single solid round wires

Robotergestützte automatisierte Herstellung von Wickelverbindungen mit einzelnen massiven Runddrähten Florian

The solderless wrapping process is an electrical connection technology. It is mainly used in applications which require high reliability, such as the aerospace industry. A single solid conductor is wrapped around a connecting terminal. The process is currently being realized manually and the worker's qualification highly determines the overall process quality and efficiency. The challenges of this specific task include the handling of the flexible wire, the production process of standard-conforming wrapped connections and the required positioning accuracy of the tool relative to the wrappost. An automation of the production process is essential to meet the increasing quality and efficiency requirements of modern production environments, however, available solutions still highly rely on the operator and therefore lack the aspired automation degree. To enable the automated production of wrapped connections, a lightweight robot is equipped with several components. In this paper, the design of the whole system, including the newly developed robotic end-effector, is presented. The main components are two wrapping tools, each driven by an electric motor and attached to an electric slide. The device can be moved onto the wrappost extending the electric slide. A wire feeder realizes the conveying movement of the wire. Moreover, an optical sensor is used to determine the wrappost's position and orientation. The newly developed system enables the automated production of wrapped connections conforming to standards.

Florian Hefner, Meike Herbert, Martin Sjarov, Robert Süß-Wolf, Jörg Franke

Towards a Framework for Evaluating Exoskeletons

Framework zur Evaluation von Exoskeletten
Niclas Hoffmann, Andreas Argubi-Wollesen, Christine Linnenberg, Robert Weidner, Jörg Franke

Robot-Based Hybrid Production Concept

Robotergestütztes hybrides Fertigungskonzept
Christian Baier, Felix Hähn, Cornelia Tepper, Matthias Weigold

Machine Learning

Frontmatter

Control loop for a databased prediction of order-specific transition times

Regelkreis für eine datenbasierte Prognose auftragsspezifischer Übergangszeiten
Frederick Sauermann, Marcel Hagemann, Jan-Philipp Prote, Günther Schuh

Data-driven Prediction of Surface Quality in Fused Deposition Modeling using Machine Learning

Datengetriebene Prädiktion der Oberflächenqualität beim Fused Deposition Modeling mittels Machine Learning
Felix Sohnius, Peter Schlegel, Max Ellerich, Robert H. Schmitt

Experimental validation of smoothed machine learning-based parameterization of local support in robot-based incremental sheet forming

Experimentelle Validierung geglätteter, auf maschinellem Lernen basierender Parametrierung des lokalen Gegenhalters in der roboterbasierten inkrementellen Blechumformung
Dennis Möllensiep, Marvin Ohm, Denis Daniel Störkle, Bernd Kuhlenkötter

Machine Learning and Artificial Intelligence in Production: Application Areas and Publicly Available Data Sets

Maschinelles Lernen und Kü nstliche Intelligenz in der Produktion: Anwendungsgebiete und öffentlich zugängliche Datensätze
Jonathan Krauß, Jonas Dorißen, Hendrik Mende, Maik Frye, Robert H. Schmitt

Camera Based Ball Screw Spindle Defect Classification System

System zur kamerabasierten Defekterkennung auf Kugelgewindetriebspindeln
Tobias Schlagenhauf, Claus-Philipp Feuring, Jonas Hillenbrand, Jürgen Fleischer

Cross-Process Quality Analysis of X-ray Tubes for Medical Applications Using Machine Learning Techniques

Prozessübergreifende Qualitätsanalyse von Röntgenstrahlern für medizinische Anwendungen auf Basis maschineller Lernverfahren
Andreas Selmaier, Phillipe Robitzch, Andreas Mayr, Jens Fürst, Jörg Franke

Development of a Machine Learning Model for a Multi-Correlative Sample-Based Prediction of Product Quality for Complex Machining Processes

Entwicklung eines Machine Learning Modells zur multikorrelativen, stichprobenbasierten Vorhersage der Produktqualität für komplexe Bearbeitungsverfahren
Jimmy Chhor, Stefan Gerdhenrichs, Felix Mohrschladt, Robert H. Schmitt

Internet of Production: Rethinking production management

Internet der Produktion: Umdenken im Produktionsmanagement
Günther Schuh, Jan-Philipp Prote, Andreas Gützlaff, Katharina Thomas, Frederick Sauermann, Niklas Rodemann

Auto-configuration of a digital twin for machine tools by intelligent crawling

Autokonfiguration eines digitalen Zwillings för Werkzeugmaschinen durch intelligentes Crawling
Philipp Gönnheimer, Jonas Hillenbrand, Thomas Betz-Mors, Philip Bischof, Lorenz Mohr, Jürgen Fleischer

Certificatiosn of AI-Supported Production Processes

Zertifizierung von KI-gestützten Produktionsprozessen
Tobias Claus Brandstätter, Jonathan Krauß, Robert H. Schmitt

Industrial Science

Frontmatter

Influencing factors for the design of agile global production networks

Einflussfaktoren für die Gestaltung agiler globaler Produktionsnetzwerke
Niklas Rodemann, Julian Ays, Andreas Gützlaff, Jan-Philipp Prote, Günther Schuh

Systematical Combination of a Lean Production System and Industry 4.0 Development of a method library to assess interactions

Systematische Verknüpfung eines Ganzheitlichen Produktionssystems und Industrie 4.0 Entwicklung einer Methodenbibliothek für die Bewertung von Interaktionen
Pascal Langlotz, Jan C. Aurich

Concept for the industrialization of physical products in the highly iterative product development

Konzept für die Industrialisierung von physischen Produkten in der hochiterativen Produktentwicklung
Shari Wlecke, Jan-Philipp Prote, Marco Molitor, Christopher Müller, Günther Schuh

Data Acquisition System in Value Streams for Resource Consumption Monitoring and Workpiece Traceability

Datenerfassungssystem in Wertströmen zur Überwachung des Ressourcenverbrauchs und der WerkstÜckrÜckverfolgbarkeit
Johannes Sossenheimer, Astrid Weyand, Markus Schreiber, Lukas Hartmann, Julia Fischer, Liselotte Schebek, Joachim Metternich, Eberhard Abele

Framework for Smart Services as a premise for collaboration in the era of manufacturing services

Framework für Smart Services als Grundlage für Kollaboration im Kontext aufkommender industrieller Dienstleistungen
Florian Stamer, Amal Labbouz, Benjamin Häfner, Gisela Lanza

Methodology for the risk and reward evaluation of industrial subscription models

Methodik zur Bewertung von Chancen und Risiken industrieller Subskriptionsmodelle
Manuel Ebi, Marius Hille, Christian Doelle, Michael Riesener, Guenther Schuh

Analysis of mobility-oriented maintenance services for complex technical systems - An empirical preliminary study

Analyse mobilitätsorientierter Instandhaltungsdienstleistung komplexer technischer Systeme - Eine empirische Vorstudie
Sebastian Herzog, Tobias Redlich, Jens P. Wulfsberg

Integrated Process for Optimized Planning of Migration in Production Networks

Ganzheitlicher Prozess zur optimierten Planung von Migration in Produktionsnetzwerken

As globalization progresses, companies are building global production networks to exploit locational advantages and successfully operate in the global market. The global market is characterised by volatility, uncertainty, complexity and ambiguity. Agile and flexible reaction to a changing environment is a success factor for global production networks that is achieved by constantly adapting the whole network. This requires continuous design and migration of production networks. Migration describes the transfer of an existing network into a planned target network. Especially interdependencies and dynamic influences as well as frequency and continuity of planning pose significant challenges for migration projects.This paper introduces an integrated process for continuous planning of migration in global production networks considering dynamic influences and interdependencies. Core element of the process is a seven-step approach for migration planning. This includes the description of the input parameters, the identification and evaluation of migration steps and interdependencies, the definition of migration rules as well as the mathematical optimization of the migration path. The continuous comparison of the predicted and actual situation guarantees a fast reaction to change and ensures the adaptability.

Judith Maibaum, Sven Cremer, Jan-Philipp Prote, Günther Schuh

Automatic Generation of Model Sets for Simulation-based Validation of New Production Planning and Control Methods

Automatische Generierung von Modellsätzen zur Validierung von neuen Methoden der Produktionsplanung und -steuerung durch Materialflusssimulationen

It is often unknown whether a new approach for production control, e. g. control strategies, leads to improvement in a real production system. Due to concerns about poor performance, it is practically impossible to test such approaches in real production. In addition, it is doubtful that testing in a single production system allows a general statement about potentials and limitations. There is a lack of a standardized method for generating validation model sets with which new approaches can be tested. To overcome this problem, this paper presents a tool for the automatic generation of simulation model sets. These model sets represent different types of production systems and thus enable the standardized and structured validation of new production planning and control methods.

Sebastian Stobrawa, Sören Wilmsmeier, Berend Denkena, Marc André Dittrich

Concept for Organizational Structures of Agile Development Networks

Konzept für Organisationsstrukturen agiler Entwicklungsnetzwerke

Today’s development projects take place in an environment characterized by with fast-paced changes of market conditions. This development leads to new challenges for the manufacturing industry, especially in high-wage countries. One response to these challenges is the adaptation of agile practices from the software industry to R&D departments of manufacturing companies. The main objectives are improved adaptability to changing requirements and a reduced time-to-market. At the same time, rising complexity of technical systems leads to a growing variety of stakeholders and competences involved in a development project. The required capabilities are increasingly provided in so-called product development networks. This paper presents a methodology to increase the innovation productivity of agile development networks by phase-oriented configuration of relevant elements of the underlying organizational structure of the network. The objective is to leverage the advantages of the mentioned approaches and to create a framework for designing agile development networks.

Maximilian Kuhn, Christian Dölle, Michael Riesener, Guenther Schuh
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